Image device

ABSTRACT

In an image device according to the invention, one end of a panel having a pixel section is extended and an external connection board connected to the extended portion, and first and second integrated circuits, each containing a driving circuit for the panel, are mounted on at least either the extended portion or the external connection board and are arranged one behind the other along a direction directed from the external connection board toward the panel. Input wiring lines for the second integrated circuit mounted nearer to the panel are passed under the first integrated circuit mounted farther from the panel, and are then connected to the second integrated circuit. Alternatively, output wiring lines from the first integrated circuit mounted farther from the panel are routed into the panel by being passed under the integrated circuit mounted nearer to the panel. This serves to greatly reduce the top plan size of the image device because the panel driving integrated circuits and the external connection board can be arranged collectively on one side of the panel.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image device comprising a panelhaving a pixel section, and more particularly to an image devicecomprising integrated circuits for supplying driving signals to thepixel section and an external connection board for supplying controlsignals to the integrated circuits.

2. Description of the Related Art

Image devices suitable for compact and thin construction have beenstrongly demanded for display devices used in portable personalcomputers, information apparatuses such as portable TVs, and terminalapparatuses such as portable telephones, or for printing devices such asthose used in printers using liquid crystal shutters or in photographicprinters (for example, photo printers) or the like. Liquid crystaldisplays, liquid crystal printers, etc. that use liquid crystals canmeet such market needs.

Under these circumstances, liquid crystal devices are commonly used asimage devices. In recent years, there has developed a need to increasethe image resolution of such liquid crystal devices so that more imageinformation can be handled while retaining the compact size of thedevice. That is, there has arisen a need to increase the number ofwiring lines in the liquid crystal panel constituting the liquid crystaldevice, while making the entire construction of the liquid crystaldevice, including its drive circuitry, thin and compact in size.Responding to such needs, many inventions have been proposed, whichinclude, for example, an image device equipped with drive circuits orcontrol circuits mounted using a COG (chip-on-glass) technique whichmounts driver ICs directly on the substrate of the liquid crystal panelconstituting the liquid crystal device, and an image device in which aflexible or rigid board with drive circuits or control circuits mountedthereon is connected to the liquid crystal panel constituting the liquidcrystal device.

Of the prior art image devices, the image device equipped with drivecircuits mounted using the COG (chip-on-glass) technique which mountsdriver ICs directly on the substrate of the liquid crystal panelconstituting the liquid crystal device will be described below, as anexample, by referring to an invention previously proposed by theApplicant and disclosed in Japanese Patent Application No. 2000-176257.

FIG. 11 is a diagram showing the structure of an essential portion of aliquid crystal display device, as prior art 1, in which driver ICs aremounted using the COG technique described above. FIG. 11(A) is a frontview, and FIG. 11(B) is a top plan view. In FIGS. 11(A) and 11(B),reference numeral 201 is a top glass substrate, 202 is a bottom glasssubstrate, 203 is a segment electrode driver IC, and 204 is a commonelectrode driver IC. Further, reference numerals 205 and 205B indicatesegment electrodes and segment electrode leads, respectively, formed onthe lower surface of the top glass substrate 201. Reference numerals 206and 206B indicate common electrodes and common electrode leads,respectively, formed on the upper surface of the bottom glass substrate202. The top glass substrate 201 and the bottom glass substrate 202 areoverlaid one on top of the other and bonded together via a sealingmember 207 made of an insulating adhesive material, leaving theirextended portions 201B and 202B extending in the vertical and horizontaldirections, respectively, as shown in the figure. A liquid crystal cellis thus constructed.

The sealing member (sealing material) 207 is formed in such a manner asto encircle the periphery of the overlaid area, leaving an injectionport opened (not shown) and thus forming a sealed space for a liquidcrystal. The top glass 201 and the bottom glass 202 hold therebetweenthe liquid crystal (not shown) injected into the sealed space, and thusform a display area 208. In the display area 208, the plurality ofsegment electrodes 205 formed on the lower surface of the top glasssubstrate 201 and the plurality of common electrodes 206 formed on theupper surface of the bottom glass substrate 202 are arrangedintersecting each other, forming a matrix array of a plurality of pixels209 and thus forming a pixel section. (By applying a prescribed voltagebetween the segment electrode 209 205 and common electrode 206corresponding to each target pixel by a known method, a desiredcharacter, graphic, etc. can be displayed).

The segment electrode leads 205B and input wiring lines 210 for thesegment electrode driver IC are formed on the lower surface of theextended portion 201 B of the top glass substrate 201. The commonelectrode leads 206B and input wiring lines 211 for the common electrodedriver IC are formed on the upper surface of the extended portion 202Bof the upper glass substrate 202. An array of protruding connectionterminals 203B not shown is provided on the bottom of the segmentelectrode driver IC 203, and the segment electrode driver IC 203 ismounted using the COG technique via an anisotropic conductive film notshown, with its connecting terminals 203B connected to the segmentelectrode leads 205B and the input wiring lines 210 for the segmentelectrode driver IC. Likewise, a similar connection terminal array 204Bis provided on the bottom of the common electrode driver IC 204, and thecommon electrode driver IC 204 is also mounted in the same manner asdescribed above, with its connecting terminals 204B connected to thecommon electrode leads 206B and the input wiring lines 211 for thecommon electrode driver IC.

The input wiring lines 210 for the segment electrode driver IC and theinput wiring lines 211 for the common electrode driver IC are eachconnected to an external circuit via a flexible printed circuit (FPC)not shown.

In the above structure, when a segment electrode driving signal isapplied from the external circuit to the segment electrode driver IC 203via the FPC through the input wiring lines 210 for the segment electrodedriver IC, the segment electrode driver IC 203 generates a segmentelectrode driving voltage, and the driving voltage is applied to eachsegment electrode 205 via the corresponding segment electrode lead 205B.Likewise, when a common electrode driving signal is applied from theexternal circuit to the common electrode driver IC 204 via thecorresponding FPC through the input wiring lines 211 for the commonelectrode driver IC, the common electrode driver IC 204 generates acommon electrode driving voltage, and the driving voltage is applied toeach common electrode 206 via the corresponding common electrode lead206B. As a result, a prescribed voltage corresponding to the drivingsignals is applied to the liquid crystal at each pixel 209 in thedisplay area 208, producing the desired display by controlling the lighttransmittance of the liquid crystal.

In this way, the liquid crystal display device shown in FIG. 11 is thinin construction and is capable of producing the necessary display.However, in this liquid crystal display device, the extended portions201B and 202B extending in the vertical and horizontal directions fromthe display area must be provided in order to mount the driver ICsthereon. As a result, the liquid crystal panel, when viewed from thetop, is not rectangular in shape, but has a complex top plan shape thatis asymmetric between left and right.

Generally, for a liquid crystal display device, a housing having asimple top plan shape such as a rectangular shape is used for theconvenience of use and for aesthetic appearance; as a result, the aboveprior art liquid crystal display device has the problem that the objectof reducing the size cannot be achieved because the top plan dimensionsof the construction, including the housing, become substantially largecompared with the display area 208.

It is known to provide a liquid crystal display device of the structureshown in FIG. 12 as prior art 2 that resolves the problem associatedwith the asymmetric shape shown in FIG. 11. In FIG. 12, referencenumeral 221 is the top glass substrate, and 222 is the bottom glasssubstrate. The top glass substrate 221 and the bottom glass substrate222 have the same horizontal width, and substantially the same verticallength. The top glass substrate 221 and the bottom glass substrate 222are not displaced horizontally, but displaced vertically relative toeach other in opposite directions, and are bonded together via thesealing member 207, leaving their extended portions 221B and 222Bexposed as shown in the figure. On the lower surface of the top glasssubstrate 221 are formed the segment electrodes 205, the segmentelectrode leads 205B which are extensions of the segment electrodes, andthe input wiring lines 210 provided independently of the segmentelectrode leads.

Here, the input wiring lines 210 are formed near the vertical edge ofthe extended portion 221B of the top glass substrate, and the segmentelectrode leads 205B are formed extending from the extended portion 221Bto the sealed area 228 enclosed by the sealing member 207, while thesegment electrodes 205 are formed within the sealed area 228.

Indicated at 206C are common electrode routing lines connecting betweenthe common electrodes 206 and the common electrode leads 206B inintegral fashion. The common electrodes 206, the common electroderouting lines 206C, the common electrode leads 205B, and the inputwiring lines 211 provided independently of the common electrode leadsare formed on the upper surface of the bottom glass substrate 221.

Here, the input wiring lines 211 are formed near the vertical edge ofthe extended portion 222B of the bottom glass substrate, and the commonelectrode leads 206B are formed extending from the extended portion 222Bto the sealed area 228 enclosed by the sealing member 207, while thecommon electrodes 206 and the common electrode routing lines 206C areformed within the sealed area 228.

In the sealed area 228, the common electrodes 206 and the segmentelectrodes 205 are arranged intersecting each other, forming a matrixarray of pixels 209 from their intersections. The common electroderouting lines 206C are formed in routing areas 230A and 230B in thesealed area 228 on the left and right sides of the display area 228comprising the pixels 209. When the number of common electrodes 206 is4n, for example, the number of common electrode routing lines in each ofthe left and right routing areas 230A and 230B is 2n. In a mannersimilar to that already described, the input wiring lines 210 and thesegment electrode leads 205B are connected to the segment electrodedriver IC 203, and the input wiring lines 211 and the common electrodeleads 206B are connected to the common electrode driver IC 204.

In the above structure, when prescribed driving signals are applied fromthe outside to the segment electrode driver IC 203 and the commonelectrode driver IC 204 through the respective input wiring lines 210and 211 in a manner similar to that previously described, the lighttransmittance of each pixel 209 in the display area 229 is controlledbased on substantially the same principle as previously described, andthe desired display is produced. As shown in FIG. 12, in the prior art2, the liquid crystal panel is symmetrical between left and right, andthe space efficiency of the housing is better than that of the liquidcrystal panel shown in FIG. 11.

In the prior art 2, since the top plan shape of the liquid crystal panelcomprising the top glass substrate 221 and bottom glass substrate 222bonded together via the sealing member 207 is substantially rectangular,the liquid crystal panel can be accommodated efficiently utilizing thespace within a housing whose top plan shape is rectangular; however,since the width is extended left and right as shown in FIG. 12, theprior art 2 has not been effective in achieving a sufficient sizereduction. This has been particularly true in the case of portabletelephones that have recently become ubiquitous in the market.

In view of this, a method has been devised that integrates the commonelectrode driving circuit and the segment driving circuit into a singleintegrated circuit. With this method, the segment driver IC 203 and thecommon electrode driver IC in FIG. 12 can be combined into one IC. Infact, products using such an IC have been around in recent years.

It will, however, be noted that while each common electrode is selectedand driven once in each frame or field period, in the same field orframe period each segment electrode is supplied with substantially asmany pulses as there are segment electrodes. For example, in the case ofa liquid crystal panel having 128 segment electrodes, up to the 128segment electrodes are selected during one common electrode selectionperiod.

In this way, the number of pulses that the segment driving circuitapplies to each segment electrode is larger than the number of pulsesthat the common electrode driving circuit applies to each commonelectrode, and as a result, if the operating voltage of the segmentdriving circuit is increased, current consumption increases, increasingthe power consumption and hence the switching noise; therefore, usuallyuse is made of a means that reduces the operating voltage of the segmentdriving circuit and relatively increases the operating voltage of thecommon electrodes.

One possible method is to integrate the common electrode driving circuitand segment driving circuit with different supply voltages or drivingcircuits with different operating voltages into a single integratedcircuit or IC, but in that case, the fabrication of the integratedcircuit becomes difficult because of noise, power consumption, and thecomplexity of the fabrication process, leading to the problem ofincreased IC cost. Furthermore, since the number of input terminals andoutput terminals on the integrated circuit increases, it is difficult toarrange the terminals within the limited surface area of the integratedcircuit, and besides, highly precise positioning of the integratedcircuit becomes necessary, resulting in the problem of increasedproduction cost. Further, if the integrated circuit is rendereddefective during the production process, etc., the expensive integratedcircuit has to be discarded as a matter of course, leading to theproblem that the cost associated with such losses increases.

Besides the above method using the COG, the method disclosed in JapaneseUnexamined Publication No. 63-184781 and described below as prior art 3has also been used as a method for supplying driving signals to theliquid crystal panel. In this method, electrode driver ICs are mountedon FPCs each of which is connected at one end to the liquid crystalpanel by an anisotropic conductive adhesive material or the like.

The prior art 3 related to the present invention will be described withreference to FIG. 13 taken from Japanese Unexamined Publication No.63-184781. In FIG. 13, the liquid crystal device 230 comprises a glasssubstrate on which common electrodes are formed, a glass substrate onwhich a plurality of segment electrodes are formed, and a liquid crystalsandwiched between the two glass substrates, thus forming a liquidcrystal display area 215. Lead electrodes for the common electrodes andsegment electrodes are formed on the four sides of one glass substrate.Circuit boards 232 constructed from FPCs with X-driver IC chips 216,Y-driver IC chips 217, and a control IC chip 218 mounted thereon areprovided on the four sides of the glass substrate, and the leadelectrodes on each circuit board 232 are connected at a connection part219 to the corresponding lead electrodes on the liquid crystal panel 231by using an anisotropic conductive adhesive material.

To connect the lead electrodes by an anisotropic conductive adhesivematerial, the anisotropic conductive adhesive material, which isprepared by mixing conductive particles and nonconductive particles in athermoplastic resin binder, is applied between the electrodes which arethen connected and bonded together under heat and pressure.

Since the electrode driver ICs are mounted on the FPCs, the prior art 3has advantages over other prior art in that a defective electrode driverIC is easily replaceable, and in that there is no need to providedwithin the liquid crystal panel the electrode driver IC mounting spacefor mounting the driver ICs using the COG technique. However, in theliquid crystal device of the prior art 3, to connect the outputs of thedriver ICs to the liquid crystal panel, extended portions are providedin the vertical and horizontal directions of the display area andconnected at at least two places to the FPCs, one for common electrodedriving and the other for segment electrode driving. The resultingproblem is that the top plan size of the liquid crystal device becomeslarge.

Generally, for a liquid crystal display device, a housing having asimple top plan shape such as a rectangular shape is used for theconvenience of use and for aesthetic appearance; as a result, the aboveprior art liquid crystal display device has the problem that the objectof reducing the size cannot be achieved because the top plan dimensionsof the construction, including the housing, become substantially largecompared with the display (pixel) area 215.

The arrangement of wiring lines on an FPC that are connected to theinput or output terminals of an electrode driver IC when mounting theelectrode driver IC on the FPC in the prior art 3 will be describedbelow as prior art 4 with reference to Japanese Unexamined PatentPublication No. 2-69720.

FIG. 14 shows a wiring pattern on the substrate side of an electrodedriver IC mounting area in a color liquid crystal panel, in whichreference numeral 241 indicates the wiring lines on the input side and242 the wiring lines on the output side. An input signal is inputthrough the input wiring lines 241 into the electrode driver IC mountedon the electrode driver IC mounting area 243, the area enclosed bydashed lines in the figure, and the signal is processed by the electrodedriver IC and output as a driving signal through the output wiring lines242. The thus output driving signal is used to drive the liquid crystal.Substantially the same wiring pattern is used for the substrate sidewiring pattern in COG mounting.

SUMMARY OF THE INVENTION

As described above, since the liquid crystal panel usually uses ahousing having a simple top plan shape such as a rectangular shape forthe convenience of use and for aesthetic appearance, the prior art imagedevice has the problem that the object of reducing the size cannot beachieved because the top plan dimensions of the construction, includingthe housing, become substantially large compared with the display area.

Furthermore, if the integrated circuit is rendered defective during theproduction process, etc., the expensive integrated circuit has to bediscarded as a matter of course, leading to the problem that the costassociated with such loss increases.

The present invention has been devised to solve the problems of theprior art image device, and an object of the invention is to provide animage device that is low cost and is small in top plan size.

According to the present invention, to solve the above-outlinedproblems, one end of a panel having a pixel section is extended and anexternal connection board connected to the extended portion, and firstand second integrated circuits, each containing a driving circuit forthe panel, are mounted on at least either the extended portion or theexternal connection board and are arranged one behind the other along adirection directed from the external connection board toward the panel.Input wiring lines for the second integrated circuit mounted nearer tothe panel are passed under the first integrated circuit mounted fartherfrom the panel, and are then connected to the second integrated circuit.Alternatively, output wiring lines from the first integrated circuitmounted farther from the panel are routed into the panel by being passedunder the integrated circuit mounted nearer to the panel.

In this way, in the image device of the present invention, as the firstand second integrated circuits are arranged one behind the other alongthe direction directed from the external connection board to the panel,and the wiring lines for one of the first and second integrated circuitsare formed by being passed under the other one of the integratedcircuits, the integrated circuits and their wiring lines can be arrangedcollectively on one side of the panel. This serves to greatly reduce thetop plan size of the image device, achieving compact image deviceconstruction.

Here, the integrated circuits need not necessarily be arranged parallelto each other with respect to the one side of the panel, but may bearranged at a certain angle to the one side of the panel or may bedisplaced relative to each other parallel to the one side of the panel.

Further, the number of integrated circuits to be mounted on at leasteither the panel extended portion or the external connection board neednot be limited to two, but three or more integrated circuits may bemounted. Moreover, if necessary, another end of the panel may beextended and an external connection board connected to the extendedportion, and the first and second integrated circuits may be mounted andarranged thereon in the same manner as earlier described.

The panel may be, for example, a liquid crystal panel, an EL panel, or aplasma display panel. Of course, the panel may be of the type thatdisplays images, or both images and characters, or only characters.Further, the panel is not limited to the type that by itself displays animage, but may be constructed, for example, as a shutter for a printer.

The external connection board may be an FPC or a rigid board. The firstand second integrated circuits are a common electrode driver IC and asegment electrode driver IC for driving the panel. Both of them may bemounted on the extended portion of the panel, or one of them may bemounted on the panel extended portion and the other on the externalconnection board; alternatively, both of them may be mounted on theexternal connection board.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will be described with reference tothe accompanying drawings, wherein:

FIG. 1 is a plan view showing an essential portion, especially a panelportion, of an image device according to a first embodiment of thepresent invention;

FIG. 2A is a cross-sectional view taken along line Y–Y′ in FIG. 1;

FIG. 2B is a perspective view of an essential portion for explaining thewiring structure in portion A in FIG. 2A;

FIG. 2C is a cross-sectional view taken along line A–A′ in FIG. 2B;

FIG. 2D is a cross-sectional view taken along line B–B′ in FIG. 2B;

FIG. 2E is a plan view of an FPC with no IC mounted thereon, forrevealing the structure in portion B in FIG. 2A;

FIG. 2F is a plan view of a common electrode driver IC as viewed fromthe pad side of the IC chip, for revealing the structure in portion B inFIG. 2A;

FIG. 2G is a plan view of an anisotropic conductive adhesive sheet, forrevealing the structure in portion B in FIG. 2A;

FIG. 3 is a plan view showing an essential portion of an image deviceaccording to a second embodiment of the present invention;

FIG. 4 is a cross-sectional view taken along line Y–Y′ in FIG. 3;

FIG. 5 is a plan view showing an essential portion of an image deviceaccording to a third embodiment of the present invention;

FIG. 6 is a cross-sectional view taken along line Y–Y′ in FIG. 5;

FIG. 7 is a plan view showing an essential portion of an image deviceaccording to a fourth embodiment of the present invention;

FIG. 8 is a cross-sectional view taken along line Y–Y′ in FIG. 7;

FIG. 9 is a plan view showing an essential portion of an image deviceaccording to a fifth embodiment of the present invention;

FIG. 10 is a diagram showing a wiring pattern on a bottom glasssubstrate in the image device shown in FIG. 9;

FIG. 11A is a front view of an image device according to first prior artrelated to the present invention;

FIG. 11B is a top plan view of the image device shown in FIG. 11A;

FIG. 12A is a top plan view of an image device according to second priorart related to the present invention;

FIG. 12B is a front view of the image device shown in FIG. 11A;

FIG. 13 is a top plan view showing an essential portion of an imagedevice according to third prior art related to the present invention;and

FIG. 14 is a diagram showing a wiring pattern on a substrate in an imagedevice according to fourth prior art related to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments of the present invention will be describedbelow with reference to the accompanying drawings. Each of theembodiments described hereinafter deals with the configuration in whichtwo integrated circuits (ICs) are arranged in a line, but it will beappreciated that the invention can be applied and the same effectobtained if the number of ICs so arranged is increased to more than two.Further, the ICs need not necessarily be arranged in a straight line,but may be displaced in directions parallel to each other or may bearranged at a certain angle relative to each other, not strictlyparallel to each other. However, arranging them in a straight line, thatis, aligning them one behind the other, has the advantage of making therouting of wiring lines less complex.

In each of the embodiments of the invention described hereinafter, thepanel of the image device is constructed from a liquid crystal panel. Asis well known, the liquid crystal panel is constructed by suitablycombining glass or plastic substrates, a sealing member, a reflectivefilm, a black matrix, electrodes, color filters, an insulating film, aplanarization film, an alignment film, etc. according to the productspecification of the panel. For simplicity of explanation, eachembodiment of the invention described herein deals with the case wherethe liquid crystal panel is constructed from the simplest set ofmembers. It will, however, be appreciated that the present invention isnot limited to the specific liquid crystal panel shown in eachembodiment, but is also applicable to image devices constructed fromother components than the liquid crystal panel, for example, imagedevices constructed from light-emitting diode arrays.

A first embodiment of the invention will be described with reference toFIG. 1 and FIGS. 2A to 2G. This embodiment shows the configuration inwhich the segment electrode driver IC chip is mounted on one of theglass substrates constituting the liquid crystal panel, while the commonelectrode driver IC chip is mounted on a flexible circuit board.

In FIG. 1 and FIGS. 2A to 2G, reference numeral 101 is the top glasssubstrate, and 102 is the bottom glass substrate; these substrates arearranged with their electrode (wiring) surfaces facing each other, andthe liquid crystal panel 100 is constructed by filling a liquid crystal110 between the substrates. In FIG. 2A, reference numeral 111 is a topalignment film formed covering the pixel electrodes on the top glasssubstrate 101, and 112 is a bottom alignment film formed on the bottomglass substrate 102.

Further, reference numeral 10 is the segment electrode driver IC chip(hereinafter called the SGDIC) which is mounted on an extended portion102B of the bottom glass substrate 102, 20B is input wiring for theSGDIC 10, and 30 is output wiring for the same. The output wiring 30 isrouted into the pixel section, forming wiring lines 33 which constitutethe segment electrodes.

In FIG. 2A, reference numeral 130 is a mold material for forming a moldcovering the SGDIC 10, and is usually made of a resin. Referencenumerals 10A and 10B are connection terminals provided on the IC chip.

The flexible printed board (hereinafter called the FPC—Flexible PrintedCircuit) as an external connection board is connected by an adhesive tothe extended portion 102B of the bottom glass substrate 102. Referencenumeral 50 is the common electrode driver IC chip (hereinafter calledthe COMIC) which is mounted on the FPC 90. As shown, in this embodiment,the COMIC 50 is mounted on the FPC 90 in such a manner as to besubstantially parallel to the SGDIC 10 mounted on the extended portion102B of the bottom glass substrate 102. Reference numeral 60 is inputwiring for the COMIC 50, and 71A and 71B are output wiring for the same.

Further, in this embodiment, input wiring 20A for the SGDIC 10 isprinted on the FPC 90, as shown in FIG. 2A; this input wiring 20A ispassed under the COMIC 50 and is connected via the connection partbetween the FPC 90 and the bottom glass substrate 102 to the inputwiring 20B for the SGDIC 10. The structure of the input wiring for theSGDIC 10 will be described later.

Next, the structures of the connection part between the top and bottomglass substrates, the connection part between the bottom glass substrateand the FPC, and the mounting part for mounting the COMIC 50 will bedescribed.

First, the connection part between the top and bottom glass substrateswill be described. As shown in FIG. 2A, the top glass substrate 101 andthe bottom glass substrate 102 are overlaid one on top of the other witha sealing member 95 placed therebetween, and the liquid crystal 110 isfilled into the gap between them. The sealing member 95 is provided withan injection hole through which the liquid crystal 110 is injected. Thesealing member 95 is prepared by mixing conductive particles 95B andnonconductive particles 95C in an insulating adhesive material (binder)95A. The conductive particles 95B provide the sealing member withelectrical conductivity in the thickness direction of the panel, whilethe nonconductive particles 95C serve to prevent the conductiveparticles 95B from connecting like a chain and shorting in directionsparallel to the substrates. With the presence of these particles, thesealing member 95 exhibits electrical conductivity anisotropy in thedirection perpendicular to the substrates. The nonconductive particles95C also function as spacers between the top and bottom glasssubstrates.

Because of this electrical conductivity anisotropy of the sealing member95, output routing wiring lines 72A and 73B for the COMIC 50, which areformed on the extended portion 102B of the bottom glass substrate 102,are connected via the sealing member 95 to output wiring lines 70A and70B for the COMIC 50, which are formed on the top glass substrate 101.As a result, the output wiring lines from the COMIC 50, formed on thebottom glass substrate 102, are transferred to the top glass substrate101.

The details of the transfer structure are shown in FIGS. 2B to 2D. FIG.2B, which shows a diagrammatic perspective view, and FIG. 2C, whichshows a cross section of an essential portion, illustrate how the outputrouting wiring lines 72A for the COMIC 50, formed on the bottom glasssubstrate 102, are connected via the sealing member 95 to the COMICoutput wiring lines 70A formed on the top glass substrate 101. The typeof liquid crystal panel in which the wiring lines formed on the bottomglass substrate 102 are connected via the sealing portion to the wiringlines formed on the top glass substrate is called the transfer typeliquid crystal panel.

On the other hand, the output routing wiring lines 30 for the SGDIC 10are formed on the bottom glass substrate 102, and are extended as thewiring lines 33 into the pixel image area, thus forming the pixelelectrodes, as previously described. In this case, as shown in FIGS. 2Band 2D, since no wiring lines are formed on the upper end of the sealingportion, a step is formed relative to the portion where the outputrouting wiring lines 70A for the COMIC 50 are formed, resulting in theformation of an uneven gap (partially even) between the top and bottomglass substrates; this can cause unevenness in the brightness of thedisplayed image. To prevent this, in the illustrated embodiment, a dummyelectrode 121 is formed on the upper end of the sealing member 95 abovethe portion where the output routing wiring lines 30 for the SGDIC 10are formed, thereby maintaining a uniform gap between the top and bottomglass substrates.

Next, the structure of the connection part between the bottom glasssubstrate 102 and the FPC 90 will be described.

As shown in FIG. 2A, the FPC 90 is connected by an anisotropicconductive adhesive 91 to the extended portion 102B of the bottom glasssubstrate 102. The anisotropic conductive adhesive 91 is a materialsimilar to the sealing material 95 used in the transfer type panelearlier described, and is prepared by mixing conductive particles 91Band nonconductive particles 91C in an insulating adhesive material 91A.The nonconductive particles 91C serve to prevent the conductiveparticles 91B from connecting like a chain and shorting in directionsparallel to the substrate. As a result, when the FPC 90 and the bottomglass substrate 102 are bonded with their wiring surfaces facing eachother, the respective wiring lines formed on the FPC 90 and thesubstrate 102 are connected together by maintaining proper electricalconnections between them.

Instead of the anisotropic conductive adhesive, connection by soldering,a conductive adhesive, or a connector may be employed, but nowadays, theanisotropic conductive adhesive is the dominant material because itrequires fewer manufacturing steps and is easy to handle. The presentinvention is unaffected by the connection method, and any of theabove-mentioned connection methods or materials may be used.

In the above embodiment of the present invention, the extended portion102B is provided on one end of the bottom substrate, but it may beprovided on the other end of the bottom substrate or on the topsubstrate; alternatively, extended portions may be provided on two ormore ends.

Next, the structure of the mounting part for the COMIC 50 will bedescribed. FIG. 2E is a plan view showing an essential portion of theFPC 90 on which the COMIC 50 is mounted, FIG. 2F is a plan view showingthe arrangement of pads on the COMIC 50, and FIG. 2G is a plan viewshowing the structure of an anisotropic conducive sheet used to mountthe COMIC 50 to the FPC 50.

In FIG. 2E, dashed line 51 indicates the mounting area for the COMIC 50.The FPC 90 is printed with the input wiring lines 60 and output wiringlines 71A, 71B for the COMIC 50 and the input wiring lines 20A for theSGDIC 10. The input wiring lines 20A for the SGDIC 10 are formed passingthrough the center of the mounting area 51 for the COMIC 50. The inputwiring lines 60 for the COMIC 50 are formed with their ends clustered inthe left and right corners of the mounting area 51, while the outputwiring lines 71A and 71B are formed with their terminal ends clusteredin the opposite left and right corners of the mounting area 51.

The COMIC 50 is provided with connection pads 52 and 53 that areclustered in the four corners of the chip, as shown in FIG. 2F. When thechip is mounted on the mounting area 51 of the FPC 50, the input pads 52are connected to the ends of the input wiring lines 60 via theanisotropic conductive sheet 93, and the output pads 53 are likewiseconnected to the ends of the output wiring lines 71A and 71B. The outputwiring lines 71A and 71B from the COMIC 50 are connected to the routingwiring lines 72A and 72B via the anisotropic adhesive 91 at theconnection part between the FPC 90 and the bottom glass substrate 102,as previously described. The number of wiring lines and the number ofterminals shown in the diagrams are for illustrative purposes only, andare not limited to those shown here.

The anisotropic conductive sheet 93 shown in FIG. 2G is formed from amaterial similar to the sealing material 95 or the anisotropicconductive adhesive 91, and is provided with electrical conductivityanisotropy by mixing conductive particles and nonconductive particles inan insulating adhesive material. Accordingly, by pressing the COMIC 50onto the FPC 90 via the sheet 93, the IC chip is mounted to the FPC 90with the pads 52 and 53 electrically connected to the respective wiringlines. Near the center of the COMIC 50, the nonconductive particlesmixed in the sheet 93 act as spacers to maintain a prescribed gapbetween the COMIC 50 and the input wiring lines 20A for the SGDIC 50.

The method of mounting the COMIC 50 on the FPC 90 is not limited to theabove mounting method; alternatively, the IC chip may be mounted by suchmeans as soldering or a conductive adhesive.

The IC chip can also be mounted to the FPC by using a TCP (Tape CarrierPackage), but in that case, since there is an opening directly below theIC chip, if wiring lines are passed under the IC, there arise problemssuch as breaks being caused in the lines and the number of wiring linescannot be increased; in the present invention, therefore, it ispreferable to mount the chip to the FPC that does not have suchproblems.

On the other hand, the SGDIC is mounted on the extended portion 102B ofthe bottom glass substrate 102 of the liquid crystal panel 100; forexample, the SGDIC can be mounted by connecting the electrodes to the ICconnection terminals (not shown) formed on the extended portion 102B, bysoldering or by means of a conductive adhesive or an anisotropicconductive adhesive. This mounting method is known as COG mounting.

The TCP used to mount the COMIC to the FPC 90 as previously describedcan also be placed in the COG mounting area. The effect of the inventioncan also be achieved by connecting a TCP to the liquid crystal panel 100in the same manner that the FPC 90 is connected to the liquid crystalpanel 100, and by mounting another TCP on the liquid crystal panel 100in the same manner that the SGDIC is mounted on the extended portion102B of the bottom glass substrate 102 of the liquid crystal panel 100.

The IC chip mounted on the bottom glass substrate is covered with theresin material 130 for protection from moisture and damage.

Instead of mounting the IC chip directly on the extended portion 102B,the driver IC may be mounted on the above-described TPC, and this TCPmay be mounted on the extended portion of the glass substrate.

All the input wiring lines 20A for the SGDIC need not be passed underthe COMIC 50, but if the FPC 90 is provided with a through-hole or atwo-layer wiring structure, the cost of the FPC 90 increases, which isnot desirable from the viewpoint of cost effectiveness. It is thereforepreferable that all the input wiring lines 20A for the SGDIC 10 bepassed under the COMIC 50 if at all possible.

It is also possible to reduce the number of SGDIC input wiring linespassing under the COMIC 50 by providing a power supply line common tothe COMIC 50 and the SGDIC 10 and by also making use of wiring lineswithin the IC or terminals on the IC; this further enhances the effectof the present invention to reduce the size of the device construction,and improves the IC mounting reliability.

The COMIC output wiring lines 71A and 71B are passed through theconnection part between the FPC 90 and the bottom glass substrate 102and routed into the liquid crystal panel 100, thus forming the COMelectrodes 73A and 73B in the pixel section. At this time, the wiringlines 72A and 72B are arranged in such a manner as to flank the SGDIC 10and the wiring lines for the SGDIC 10, as shown in FIG. 1.

This structure serves to reduce the size of the extended portion 102B,and by bending the FPC 90, the size of the image device can be furtherreduced.

The structure also offers a cost advantage, since the size can bereduced without integrating the SGDIC 10 and the COMIC 50 into a singlechip.

Further, when a driving method is used that applies a high voltage tothe COMIC 50 and a low voltage to the SGDIC 10, since the COMIC 50,having a higher risk of breakdown due to the high voltage, is mounted onthe FPC 90, the IC, if broken, can be easily replaced, which isadvantageous in terms of cost.

A second embodiment of the present invention will be described withreference to FIGS. 3 and 4. In the second embodiment, the SGDIC 10 andthe COMIC 50 are both mounted on the FPC 90, and the COG mountingemployed in the first embodiment is not implemented here. FIG. 3 alsodepicts the wiring for the pixel section in detail which was not shownin FIG. 1.

In addition to the feature that not only the COMIC 50 but also the SGDIC10 is mounted on the FPC 90 as shown in FIGS. 3 and 4, the embodimenthas the following feature.

The input wiring lines 60 for the COMIC 50 and the input wiring lines 20for the SGDIC 10 are formed on the FPC 90. The input wiring lines 60 forthe COMIC 50 are directly connected to the input terminals of the COMIC50 mounted on the FPC 90.

The input wiring lines 20 for the SGDIC 10 are passed under the COMIC 50mounted on the FPC 90, and connected to the input terminals of the SGDIC10 mounted on the FPC 90.

The output wiring lines from the COMIC 50 are split between the outputwiring lines 71A for the COMIC 50 passing in the left-hand part in FIG.3 and the output wiring lines 71B for the COMIC 50 passing in theright-hand part in FIG. 3, and the output wiring lines 71A and 71B arethen passed through the anisotropic conductive adhesive 91, i.e., theconnection part between the FPC 90 and the bottom glass substrate 102,and routed as the COMIC output routing lines 72A and 72B in the liquidcrystal panel 100, forming the COM electrodes 73A and 73B in the pixelsection.

With the above wiring, the COM electrodes 73A are arranged as one blockin the upper part in FIG. 3 and the COM electrodes 73B are arranged asone block in the lower part, the two blocks thus forming the entirearray of COM electrodes.

Whether the COM electrodes are arranged into two blocks or not should bedetermined by determining the optimum value as the specification basedon the size and shape of the liquid crystal panel, the number ofelectrodes, and the electrode density. Of course, the entire array ofCOM electrodes may be configured as one block.

On the other hand, the wiring lines for the SGDIC 10 are first passedunder the COMIC 50 and then connected to the input terminals of theSGDIC 10 mounted on the FPC 90.

The output wiring lines from the SGDIC 10 are routed within the FPC 90as the output routing lines 31 for the SGDIC 10, and the output routinglines 31 are then passed through the anisotropic conductive adhesive 91,i.e., the connection part between the FPC 90 and the bottom glasssubstrate 102, and routed as the SGDIC output routing lines 32 in theliquid crystal panel 100, forming the SGD electrodes 33 in the pixelsection.

This structure serves to reduce the size of the extended portion 102B;further, by bending the FPC 90, the size of the image device can begreatly reduced.

The structure also offers a cost advantage, since the size can bereduced without integrating the SGDIC and the COMIC into a single chip.

Furthermore, since the SGDIC 10 and the COMIC 50 are both mounted on theFPC 90, the ICs, if broken, can be easily replaced, which isadvantageous in terms of cost.

A third embodiment of the present invention will be described withreference to FIGS. 5 and 6. In the third embodiment, as in the secondembodiment, the SGDIC 10 and the COMIC 50 are both mounted on the FPC90, and the COG mounting employed in the first embodiment is notimplemented here. The third embodiment differs from the secondembodiment in the wiring for the pixel section. Therefore, the thirdembodiment will be described focusing on differences from the secondembodiment shown in FIGS. 3 and 4.

The input wiring lines 60 for the COMIC 50 and the input wiring lines 20for the SGDIC 10 are formed on the FPC 90. The input wiring lines 60 forthe COMIC 50 are directly connected to the input terminals of the COMIC50 mounted on the FPC 90.

The input wiring lines 20 for the SGDIC 10 are passed under the COMIC 50mounted on the FPC 90, and connected to the input terminals of the SGDIC10 mounted on the FPC 90.

The output wiring lines 70 from the COMIC 50 are split between theoutput wiring lines 71A for the COMIC 50 passing in the left-hand partin FIG. 5 and the output wiring lines 71B for the COMIC 50 passing inthe right-hand part in FIG. 5, and the output wiring lines 71A and 71B,after being routed within the FPC 90, are passed through the anisotropicconductive adhesive 91, i.e., the connection part between the FPC 90 andthe bottom glass substrate 102, and routed as the COMIC output routinglines 72A and 72B in the liquid crystal panel 100, forming the COMelectrodes 73A and 73B which form pixels.

With the above wiring, one COM electrode 73A is arranged in theuppermost row in FIG. 5, then one COM electrode 73B is arranged in thenext row; by repeating this pattern, the COM electrodes 73A and the COMelectrodes 73B are arranged alternately, first from the left-sidewiring, then from the right-side wiring, and so on, as shown in thefigure.

In the third embodiment, the electrodes are arranged with one wiringline from the left-side wiring alternating with one wiring line from theright-side wiring, but they may be arranged in such a manner that agroup of n wiring lines, for example, two or three wiring lines, fromthe left-side wiring alternates with a group of n wiring lines, forexample, two or three wiring lines, from the right-side wiring; in thiscase, the value of n can be determined appropriately according to thespecification of the liquid crystal panel.

This structure serves to reduce the size of the extended portion 102B;further, by bending the FPC 90, the size of the image device can begreatly reduced.

The structure also offers a cost advantage, since the size can bereduced without integrating the SGDIC 10 and the COMIC 50 into a singlechip.

Furthermore, since the SGDIC 10 and the COMIC 50 are both mounted on theFPC 90, the ICs, if broken, can be easily replaced, which isadvantageous in terms of cost.

In the second embodiment, brightness unevenness may occur at theboundary between the blocks, mainly due to the difference in wiringresistance. The third embodiment has the effect of being able toeliminate such brightness unevenness between the blocks.

A fourth embodiment of the present invention will be described withreference to FIGS. 7 and 8.

While, in the second embodiment, the SGDIC 10 and the COMIC 50 are bothmounted on the FPC 90, in the fourth embodiment the SGDIC 10 and theCOMIC 50 are both mounted on the liquid crystal panel 100.

In addition to the feature that not only the SGDIC 10 but also the COMIC50 is mounted on the liquid crystal panel 100 as shown in FIGS. 7 and 8,the embodiment has the following feature.

The input wiring lines 60 for the COMIC 50 and the input wiring lines 20for the SGDIC 10 are formed on the FPC 90 and, after being routed withinthe FPC 90, the input wiring lines are connected into the liquid crystalpanel 100 via the anisotropic conductive adhesive 91, i.e., theconnection part between the FPC 90 and the bottom glass substrate 102.

The input wiring lines 60 for the COMIC 50 are routed into the liquidcrystal panel 100 via the anisotropic conductive adhesive 91, i.e., theconnection part between the FPC 90 and the bottom glass substrate 102,and connected to the input terminals of the COMIC 50 mounted on theextended portion 102B.

On the other hand, the input wiring lines 20 for the SGDIC 10 are routedinto the liquid crystal panel 100 via the anisotropic conductiveadhesive 91, i.e., the connection part between the FPC 90 and the bottomglass substrate 102, and then routed as the input wiring lines 22 forthe SGDIC 10 on the extended portion 102B; the input wiring lines 22 arepassed under the COMIC 50 mounted on the extended portion 102B, andconnected to the input terminals of the SGDIC 10 mounted on the extendedportion 102B.

The output wiring lines 72A and 72B from the COMIC 50 are routedseparately as the COMIC output wiring lines 70A passing in the left-handpart in FIG. 7 and the COMIC output wiring lines 70B passing in theright-hand part in FIG. 7 and, after being routed within the liquidcrystal panel 100 as the output routing lines 72A and 72B for the COMIC50, are connected to the COM electrodes 73A and 73B which form pixels.

With the above wiring, the COM electrodes 73A are arranged as one blockin the upper part in FIG. 7 and the COM electrodes 73B are arranged asone block in the lower part in FIG. 7, the two blocks thus forming theentire array of COM electrodes.

Whether the COM electrodes are arranged into two blocks or not should bedetermined by determining the optimum value as the specification basedon the size and shape of the liquid crystal panel, the number ofelectrodes, and the electrode density. Of course, the entire array ofCOM electrodes may be configured as one block.

On the other hand, the wiring lines for the SGDIC 10 are first passedunder the COMIC 50 and then connected to the input terminals of theSGDIC 10 mounted on the extended portion 102B.

The output wiring lines 30 from the SGDIC are routed within the liquidcrystal panel 100 as the SGDIC output routing lines 32, and form the SGDelectrodes 33 in the pixel section.

In the above structure, while the extended portion 102B becomes largerthan that of the second embodiment, there is no need to handle FPCs withintegrated circuits (ICs) mounted thereon but it is only necessary tohandle the liquid crystal panel (an FPC with no ICs mounted thereon maybe attached to it), offering the advantage of easy handling and lowmanufacturing cost.

Furthermore, since the output wiring lines 30 from the SGDIC 10 are notrouted via the FPC 90, the above structure is suited to the constructionwhere the number of output wiring lines 30 for the SGDIC 10 is large.

Another advantage is that the thickness of the image device can befurther reduced by holding the thickness of the ICs to within thethickness of the top glass substrate 101.

The structure also offers a cost advantage, since the size can bereduced without integrating the SGDIC 10 and the COMIC 50 into a singlechip.

Furthermore, since the SGDIC 10 and the COMIC 50 are both mounted on theextended portion 102B of the liquid crystal panel 100, the structure hasthe advantage of being able to reduce the cost because the mounting ofthe SGDIC 10 and the mounting of the COMIC 50 can be accomplished in asingle mounting step.

In the first to fourth embodiments described above, the input wiringlines for the SGDIC 10 are passed under the COMIC 50, but the presentinvention can also be carried out and the same effect obtained in otherways. FIGS. 4, 6, and 8 given above are diagrams showing thecross-sectional structure of the essential portion of the panel.

A fifth embodiment of the present invention will be described withreference to FIG. 9.

In the foregoing fourth embodiment, the input wiring lines 22 for theSGDIC 10 are passed under the COMIC 50 and connected to the inputterminals of the SGDIC 10; in contrast, in the fifth embodiment, theoutput wiring lines 30 from the SGDIC 10 are passed under the COMIC 50and thereafter connected to the SGD electrodes 33.

In addition to the feature that not only the SGDIC 10 but also the COMIC50 is mounted on the liquid crystal panel 100 as shown in FIG. 9, theembodiment has the following feature.

The input wiring lines 60 for the COMIC 50 and the input wiring lines 20for the SGDIC 10 are formed on the FPC 90 and, after being routed withinthe FPC 90, the input wiring lines are connected into the liquid crystalpanel 100 via the anisotropic conductive adhesive 91, i.e., theconnection part between the FPC 90 and the bottom glass substrate 102.

The input wiring lines 60 for the COMIC 50 are routed into the liquidcrystal panel 100 via the anisotropic conductive adhesive 91, i.e., theconnection part between the FPC 90 and the bottom glass substrate 102,and connected to the input terminals of the COMIC 50 mounted on theextended portion 102B.

On the other hand, the wiring lines 21 on the FPC 90, which constitutethe input wiring lines 20 for the SGDIC 10, are routed into the liquidcrystal panel 100 via the anisotropic conductive adhesive 91, i.e., theconnection part between the FPC 90 and the bottom glass substrate 102,and then routed as the input wiring lines 22 for the SGDIC 10 on theextended portion 102B and connected to the input terminals of the SGDIC10 mounted on the extended portion 102B.

The output wiring lines 70A and 70B from the COMIC 50 are routedseparately as the COMIC output wiring lines 70A passing in the left-handpart in FIG. 9 and the COMIC output wiring lines 70B passing in theright-hand part in FIG. 9 and, after being routed within the liquidcrystal panel 100 as the output routing lines 72A and 72B for the COMIC50, are connected to the COM electrodes 73A and 73B which form pixels.

With the above wiring, the COM electrodes 73A are arranged as one blockin the upper part in FIG. 7 and the COM electrodes 73B are arranged asone block in the lower part in FIG. 7, the two blocks thus forming theentire array of COM electrodes.

Whether the COM electrodes are arranged into two blocks or not should bedetermined by determining the optimum value as the specification basedon the size and shape of the liquid crystal panel, the number ofelectrodes, and the electrode density. Of course, the entire array ofCOM electrodes may be configured as one block.

On the other hand, the output wiring lines 30 from the SGDIC 10 arepassed under the COMIC 50 mounted on the extended portion 102B and,after being routed within the liquid crystal panel 100 as the outputrouting lines 32 for the SGDIC 10, are connected to the SGD electrodeswhich form pixels.

In the above structure, while the extended portion 102B becomes largerthan that of the second embodiment, there is no need to handle FPCs withintegrated circuits (ICs) mounted thereon but it is only necessary tohandle the liquid crystal panel (though an FPC with no ICs mountedthereon is attached to it), offering the advantage of easy handling.

Furthermore, since the output wiring lines 30 from the SGDIC 10 are notrouted via the FPC 90, the above structure is suited to the constructionwhere the number of output wiring lines 30 for the SGDIC 10 is large.

Another advantage is that the thickness of the image device can befurther reduced by holding the thickness of the ICs to within thethickness of the top glass substrate 101.

The structure also offers a cost advantage, since the size can bereduced without integrating the SGDIC 10 and the COMIC 50 into a singlechip.

Furthermore, since the SGDIC 10 and the COMIC 50 are both mounted on theextended portion 102B of the liquid crystal panel 100, the structure hasthe advantage of being able to reduce the cost because the mounting ofthe SGDIC 10 and the mounting of the COMIC 50 can be accomplished in asingle mounting step.

Whether to use the fourth embodiment or the fifth embodiment isdetermined appropriately according to the number of terminals on theSGDIC 10 and COMIC 50, the number of terminals in the vertical andhorizontal directions of the liquid crystal panel, the electrode width,the aspect ratio of the pixel section, etc.

FIG. 10 is a diagram showing the wiring lines in the IC mounting areafor explaining the wiring pattern in the area on the bottom glasssubstrate where the electrode driver ICs are mounted as illustrated inFIG. 9 that showed a plan view of the structure of the fifth embodiment.

The wiring pattern shown in FIG. 10 is not specifically limited to theembodiment of FIG. 9, but is also applicable to any of the first tofourth embodiments.

A description will be given with reference to FIG. 10 while alsoreferring to FIG. 9 as needed.

In FIG. 10, dashed line 55 shows the position where the COMIC 50 ismounted, while dashed line 11 shows the position where the SGDIC 10 ismounted. The input wiring lines 60 for the COMIC 50 are routed into theliquid crystal panel 100 via the anisotropic conductive adhesive 91,i.e., the connection part between the FPC 90 and the bottom glasssubstrate 102, and connected to the COMIC 50 mounted on the extendedportion 102B.

On the other hand, the input wiring lines 20 for the SGDIC 10 areconnected to the input terminals of the SGDIC 10 mounted on the extendedportion 102B.

The output routing wiring lines 72A and 72B from the COMIC 50, whoseends are connected to the output terminals of the COMIC 50, are routedthrough the liquid crystal panel 110 and connected to the COM electrodes73A and 73B which form pixels as shown in FIG. 9.

The output routing wiring lines 32 from the output terminals of theSGDIC 10 are passed under the COMIC 50 mounted on the extended portion102B, and are routed through the liquid crystal panel 100 and connectedto the SGD electrodes 33 which form pixels.

In FIG. 10, the input/output terminals of the COMIC are clustered in thefour corners of the COMIC so that a larger number of wiring lines fromthe SGDIC 10 can be passed under the COMIC. This feature has the effectof further reducing the size of the image device. On the other hand, thenumber of wiring lines passing under the COMIC can be reduced toincrease the spacing between the wiring lines and thereby preventshorting, etc. and enhance the reliability.

Furthermore, by inserting a gap adjusting spacer between the IC and thesubstrate, the wiring lines passing under the IC can be prevented frombeing damaged and disconnected by the overlying IC.

As the spacer to be mounted on the liquid crystal panel, use can bemade, for example, of a color filter, an insulating film, an alignmentfilm, a light blocking film, a reflective film, or a sealing member;since this can eliminate the step of attaching the spacer, the structureoffers the advantage of being able to achieve a cost reduction and animprovement in reliability.

If the mounting adhesive used to mount the IC is also used as the spacermaterial by mixing therein nonconductive particles having a suitableparticle size, anisotropic conductive adhesion with a constant thicknessor gap can be accomplished. This not only achieves reliable mounting butcan also reduce the number of manufacturing steps.

It is also possible to prevent shorting between the routing wiring lines32 and the COMIC 50 by covering the routing wiring lines 32 passingunder the COMIC 50 with an insulating film. Alternatively, the surfaceof the COMIC 50, excluding its terminal portions (for example, the pads52 in FIG. 2F), may be covered with an insulating film. Further, theinsulating film may be formed not only on the surface of the IC but alsoon the wiring lines.

In FIG. 2F, the input/output terminals of the COMIC are clustered in thefour corners of the IC chip, that is, no input/output terminals areformed in the center portions of the longer sides of the COMIC.Accordingly, wiring lines for the SGDIC 10 may be formed in theseportions. In that case, the output wiring lines from the SGDIC 10 can berouted to the panel via the wiring lines formed on the COMIC. Thisstructure serves to prevent shorting between the IC and the wiring linespassing under the IC and thereby improve not only the reliability of themounting but also the reliability of the image device.

In the above embodiments, the SGDIC has been shown as incorporating thesegment electrode driving circuit, but in addition to that, a memorycircuit and a control circuit may also be incorporated into the SGDIC.

Likewise, in the above embodiments, the COMIC has been shown asincorporating the common electrode driving circuit, but in addition tothat, a memory circuit and a control circuit may also be incorporatedinto the COMIC.

Preferably, circuits requiring a high operating voltage should beincorporated in the COMIC and lower voltage circuits in the SGDIC.

ADVANTAGEOUS EFFECT OF THE INVENTION

As described above with reference to the preferred embodiments, in theimage device of the present invention, the integrated circuits fordriving the panel are arranged substantially parallel to each other onone side of the panel. Accordingly, the external connection board forsupplying external signals to these integrated circuits need only beconnected to the one side of the panel. As a result, the top plandimensions of the image device of the invention become substantiallysmaller compared with the prior art device, greatly contributing toreducing the cost and the size of the entire construction.

1. A display device comprising: a panel having a display area in whichfirst electrodes and second electrodes are disposed in matrix form; afirst integrated circuit for driving said first electrodes; a secondintegrated circuit for driving said second electrodes; and input wiringlines for said first and second integrated circuits; wherein in adirection from an end of the panel towards said display area, said firstintegrated circuit is disposed nearer to said display area than saidsecond integrated circuit and said second integrated circuit is disposedfarther from said display area than said first integrated circuit; andsaid input wiring lines for said first integrated circuit are passedunder said second integrated circuit.
 2. A display device as claimed inclaim 1, wherein said output wiring lines from said second integratedcircuit mounted farther from said display area are routed to saiddisplay area by being passed under said first integrated circuit mountednearer to said display area.
 3. A display device as claimed in claim 1,wherein said first and second integrated circuits are arranged onebehind the other along a direction directed from an end of the paneltoward said display area, and at least a part of said first integratedcircuit is positioned on an extension of the panel.
 4. A display deviceas claimed in claim 3, wherein said input wiring lines for said firstintegrated circuit mounted nearer to said display area are passed undersaid second integrated circuit mounted father from said display area,and are then connected to said first integrated circuit mounted nearerto said display area.
 5. A display device as claimed in claim 1 or 4,wherein connection terminals on said second integrated circuit underwhich said input wiring lines are passed are formed near four corners ofsaid second integrated circuit.
 6. A display device as claimed in claim2 or 1, wherein said panel includes opposed substrates, one substratehas an extended portion extending from one end thereof and protrudingbeyond a corresponding end of the other substrate, and said panel andsaid external connection board are connected together at said extendedportion with their wiring surfaces facing each other.
 7. A displaydevice as claimed in claim 6, wherein at least one of said first andsecond integrated circuits is mounted on said extended portion.
 8. Adisplay device as claimed in claim 6, wherein at least one of said firstand second integrated circuits is mounted on said external connectionboard.
 9. A display device comprising: a panel having a display area inwhich first electrodes and second electrodes are disposed in matrixform; an external connection board connected to said panel; a firstintegrated circuit for driving said first electrodes; a secondintegrated circuit for driving said second electrodes; and input wiringlines for said first and second integrated circuits; wherein, in adirection from said external connection board towards said display area,said first integrated circuit is disposed nearer to said display areathan said second integrated circuit and said second integrated circuitis disposed farther from said display area than said first integratedcircuit; and said output wiring lines from said second integratedcircuit mounted farther from said display area are routed to saiddisplay area by being passed under said first integrated circuit mountednearer to said display area.
 10. A display device as claimed in any oneof claims 2, 1, 3, 4, and 9, wherein said panel is constructed byarranging a segment electrode and a common electrode opposite each otherbetween two substrates.
 11. A display device as claimed in claim 10,wherein one of said first and second integrated circuits is a segmentelectrode driving integrated circuit for driving said segment electrode,and the other is a common electrode driving integrated circuit fordriving said common electrode.
 12. A display device as claimed in claim10, wherein said first integrated circuit mounted nearer to said displayarea is the segment electrode driving integrated circuit.
 13. A displaydevice comprising: a panel having a display area in which firstelectrodes and second electrodes are disposed in a matrix form; anexternal connection board connected to said panel; a first integratedcircuit for driving said first electrodes; a second integrated circuitfor driving said second electrodes; and input wiring lines for saidfirst and second integrated circuits, wherein said panel includes twosubstrates facing each other, one of the two substrates having anextended portion extending from one end thereof and protruding beyond acorresponding end of the other substrate, said panel and said externalconnection board being connected together at said extended portion withtheir wiring surfaces facing each other, said first integrated circuitbeing mounted on said extended portion, and said second integratedcircuit being mounted on said external connection board; and whereinsaid input wiring lines of said first integrated circuit, which isdisposed nearer to said panel than said second integrated circuit areconnected to said first integrated circuit by passing under a surface ofsaid second integrated circuit, said surface facing to said externalconnection board.
 14. A display device as claimed in claim 13, whereinsaid first integrated circuit is a segment electrode driving integratedcircuit.